Abstract: An improved self-unloading spreader has a front end, a back end, and sides defining walls of a container for holding material. The container has at least one opening in one of the walls through which material can move. Inside of the container, longitudinally disposed between the front end and the rear end, is an auger that can move material in the container to and through the opening. Also inside of the container, adjustably positioned above the auger, is an adjustable height baffle to control the amount of material the auger has available to move. Outside of the container, adjacent to the opening, is a transversely mounted conveyer belt for spreading material that flows through the opening. An hydraulic system powers the auger and allows the hydraulically powered auger to either move material towards the opening or away from the opening. The auger, in combination with the adjustable height baffle, controls the rate at which material is provided to the conveyer system.